<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <link rel="stylesheet" href="./static/bootstrap/css/bootstrap.min.css">
    <script src="static/js/jquery.min.js"></script>
    <script src="static/bootstrap/js/bootstrap.min.js"></script>
    <style>
        button{
            position: absolute;
            bottom: 0;
        }
    </style>
</head>
<body>

<br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br>
<button>计算</button>

<script>


    $(function(){
        $(window).bind('scroll',function(){show()});

        function  show(){
            var Sheight = $(window).scrollTop();       //滚动条到顶部的高度
            var Wheight = $(window).height();        //窗口的高度
            var dHeight = $(document).height();         //文档的高度
            if(Sheight+Wheight == dHeight){
                alert("底部了");
            }
        }
    })
</script>
</body>
</html>